Blob()

The Blob() constructor creates a Blob object, which represents a file-like object of immutable, raw data.

Syntax

new Blob()
new Blob(array)
new Blob(array, options)

Note: Blob() can only be constructed with new. Attempting to call it without new throws a TypeError.

Parameters

• array optional

  • : An array of values to include in the Blob. These can be ArrayBuffer, Blob, or strings. If any of these elements is a Blob, its content (and not the object itself) is copied into the Blob being constructed.

• options optional

  • : An object containing optional attributes for the Blob.
    • type
      • : A string indicating the MIME type of the data. The default value is the empty string "".
    • endings
      • : A string indicating how to handle line endings in the data. This can be either "transparent" (default) to keep line endings unchanged, or "native" to convert line endings to the platform's native line endings (e.g., \r\n on Windows).

Return value

A new Blob object containing the specified data.

Description

Blob objects represent data that isn't necessarily in a JavaScript-native format. The File interface is based on Blob, inheriting its functionality and expanding it to support files on the user's system.

To construct a Blob from other non-blob objects and data, use the Blob() constructor. To create a blob that contains a subset of another blob's data, use the slice() method.

The type property of a Blob object will match the MIME type specified in the constructor's options parameter, defaulting to an empty string if not specified.